It took a whole evening of mocking (participators included; sink, toothbrushes, table/bench, mirror, tiles, and a good group of people) up to decide on the final tile positions (they are going to frame a sink and mirror). The language used to define the layout was amazing. The arrangement/form emerged slowly with some tiles being fixed quickly and others as the evening rolled on.
The next morning we did a final mock up on the wall (sink and cabinet included) before setting them into a layer of earthen plaster.